Magnet mounting arrangement for magnetrons



Dec. 2, 1947. D. JACKSON 2,431,304

' MAGNET MOUNTING ARRANGEMENT FOR MAGNETRONS Filed April 4, 1945 2Sheets-Sheet l Inventor pjz agsorf.

A tto rneys Dec. 2, 1947. D. A K O v 2,431,804

MAGNET MOUNTING ARRANGEMENT FOR MAGNETRONS Filed April 4, 1945 2Shets-Sheet 2 V 1 I, J83 o 6 3' I0 1 5 S 4 I I Patented Dec. 2, 1947MAGNET MOUNTING ARRANGEMENT FOR MAGNETRONS Donald .iackson, Cambridge,England, assignor to Pye Limited, Cambridge, England, a British com panyApplication April 4, 1945, Serial No. 586,609

In Great Britain March 20, 1944 Claims.

The present invention relates to an arrangement for mounting magnetsused in conjunction with electron discharge devices, such as thermionicvalves of the magnetron type, whereby the position of the magnetrelative to the discharge device may be easily adjusted and whereby themagnet may be moved away from its normal position to enable the valve tobe readily removed or interchanged.

According to the present invention the magnet is mounted on a memberwhich is rotatable about the axis of the electron discharge device whenit is mounted in position, or about the axis of the holder for theelectron discharge device, whereby the radial position of the magnetrelative to the electron discharge device may be readily adjusted, themagnet being bodily movable on the said member so that it can be movedaway from the discharge device when it is desired to remove the latter.Preferably, means are provided for looking the magnet in the position itshould occupy when the electron discharge device is in operation.

In the preferred form of the invention, the magnet is mounted so as tobe longitudinally slidable in grooves formed in a member which ismounted to rotate about the axis of the holder for the electrondischarge device. The rotatable movement of the member may be limited toa few degrees since only slight re-adjustment is necessary if a newdischarge device is inserted in the holder to bring the magnet intocorrect radial position with respect to the electrodes therein. Meansmay be provided for locking the member in the adjusted position, forexample by means of. one or more screws passing through an arcuate slotin the member and screwing into the base plate or chassis which carriesthe Valve holder. The magnet may be locked in any desired position inthe slots and this ma be conveniently effected by a cam operated member.

In order that the invention may be more clearly understood, referencewill now be made, by way of example, to the accompanying drawings, inwhich:

Fig, 1 shows a side elevation, partly in section, of one form of theinvention, with the magnet moved only part way towards its operatingposition.

Fig. 2 shows a plan view of Fig. 1.

Fig. 3 shows a perspective view with the magnet retracted and the valvepartly removed.

Fig. 4 shows a plan view of a modification embodying two magnets.

Referring to the embodiment illustrated in Figs, 1, 2 and 3 which showan arrangement for use in connection with a valve I having an anode disc2 extending outside the valve envelope, the disc 2 is adapted to fit ina circular cup-shaped holder 3 carried by a base member shown in theform of a box-like casing 4. The holder 3 is provided with one or moreupturned lugs 5 which are adapted to engage in apertures B in the disc 2on the valve so as to locate it in the approximately correct positionrelative to the magnet l.

The valve I is held in position by inserting an inverted cup-shapedcover 8 into the top of the cup-shaped holder 3 and securing it therein,for example by a bayonet fitting comprising the projection 9 on the sideof the cover 8 and slots Iii in the flange of the holder 3. A ring I Iis fitted within the cover 8 and retained by a. small flange I2 thereon,a spring I3 being provided for urging the ring II into firm contact withthe anode disc 2 to hold the valve firmly in position in the holder 3when the cover is inserted therein. The cover may be provided with atubular extension I4 which encloses the remainder of the valve envelope.The cover and the extension are made of non-magnetic material.

The magnet I, which may conveniently be of horseshoe shape, is carriedby a supporting plate I5 which may be made of a metal stamping and hasan aperture l6 which fits over and bears against the outer surface ofthe valve holder 3, whereby the member I5 may be rotated about the axis.of the valve holder. The supporting plate i5 is provided with arcuateslots IT, I8 at each end through which pass screws I9, 2e threaded intothe base 4, whereby the plate member may be locked in any adjustedposition.

The magnet I is carried by the supporting Plate I5 so as to be slidablein grooves or slots 2! formed in the supporting plate and extendingradially away from the valve holder 3. The magnet is secured between twoplates 22, 23 by means of three screws 24. Two headed spindles 25 withtheir heads 26 arranged beneath the two slots 2| in the plate I5 extendthrough apertures in the two plates 22 and 23 and are pivotallyconnected at their upper ends to a locking handle 21 shaped as shown inFig. 3, the downwardly extending portions 28 of the handle being camshaped so that when the handle is in the vertical position the rods arefree and allow the magnet to be moved radially towards or away from thevalve holder whilst when the handle is lowered to the position shown inthe drawings the rods are tensioned such that their heads engage firmlybeneath the slots 2| to lock the magnet assembly in the adjustedposition, A further slot 21a is also provided in the plate l with whicha projection, for example the screw 29, engages in order to prevent themagnet assembly from turning relative to the plate.

By means of the arrangement described the magnet may be slid up towardsthe valve to emibrace the extension l4 between the centres of the magnetpole pieces (Figs. 1 and 2 show the magnet only partially advancedtowards this position) and locked in position by depressing the handle21, and the whole assembly may be adjusted radially by loosening thescrews I9 and 20 and rotating the plate relative to the valve holder.When the desired adjustment is attained the screws I9 and 29 are againtightened. By releasing the handle 2'! the magnet may readily be slidaway from the valve to permit the cover and valve to be removed.

Fig. 4 shows a modification in which two magnets 1, la are employed.These are mounted on a double ended plate 15a, the centre of which isapertured to rotate around the valve holder 3 and opposite ends of whichare provided with arcuate slots 18 and l8a with corresponding lockingscrews 20, 20a for locking the plate in the adjusted position. Eachmagnet I, la is mounted on the plate l5a as described above and each maybe moved radially towards and away from the valve holder by releasingthe corresponding cam looking handle 2'! or 27a.

Although particular embodiments of the invention have been described byway of example, it will be understood that various modifications may bemade without departing from the scope of the invention as defined by theappended claims.

I claim:

1. Arrangement for mounting magnets used in conjunction with electrondischarge devices, comprising a holder for an electron discharge device,a supportin plate mounted for rotation about said holder, means forlocking the supporting plate in an adjusted position relative to saidholder, a magnet carried by the supporting plate and moveable in guidesthereon in a direction towards and away from the holder, and means forlocking the magnet in an adjusted position relative to the supportingplate.

2. Arrangement for mounting magnets used in conjunction with electrondischarge devices, comprising a holder for an electron discharge devicesecured to a base plate and projecting therefrom, a supporting platehaving an aperture rotatably engaging with the external surface of saidholder, means for locking the supporting plate against movement relativeto the base plate, a magnet carried by the supporting plate and moveablein guides thereon in direction towards and away from the holder, andmeans for locking the magnet against movement relative to the supportingplate.

3. Arrangement for mounting magnets used in conjunction with electrondischarge devices, comprising a holder for the electron discharge devicesecured to a base plate and projecting therefrom, a supporting platehaving an aperture rotatably engaging with the external surface of theholder, at least one arcuate slot in said supporting plate, screw meanscooperating with the base plate and passing through said arcuate slotfor locking the supporting plate in its adjusted position, a magnetcarried by the supporting plate and moveable in guide slots formedtherein which extend in a direction towards and away from the holder,and cam operated means for locking the magnet relative to the supportingplate.

4. Arrangement for mounting magnets used in conjunction with electrondischarge devices, comprising a holder for the electron dischargedevice, a supporting plate mounted for rotation about said holder, meansfor locking the supporting plate in an adjusted position relative tosaid holder, a magnet carried by the supporting plate and moveable inguide slots formed therein which extend in a direction towards and awayfrom the holder, and means for locking the magnet relative to thesupporting plate.

5. Arrangement for mounting magnets used in conjunction with electrondischarge devices, comprising a holder for the electron discharge devicesecured to a base plate and projecting therefrom, a supporting platehaving an aperture rotatably engaging with the external surface of theholder, at least one arcuate slot in said supporting plate screw meanscooperating with the base plate passing through said arcuate slot forlocking the supporting plate in its adjusted position, a magnet carriedby the supporting plate and moveable along guides thereon which extendin a direction towards and away from the holder, and means for lockingthe magnet relative to the supporting plate.

DONALD JACKSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,192,450 Parsons et a1. July 25,1916 1,720,824 Donle July 16, 1929 1,742.662 Miller Jan. 7, 19301,985,093 Hehlgans Dec. 18, 1934 2,064,012 Kilgore Dec. 15, 19362,100,162 Fritz Nov, 23, 1937 2,114,035 Skellett Apr. 12, 1938 2.142345Braden Jan. 3, 1939 2,225,689 Demuth Dec. 24, 1940 FOREIGN PATENTSNumber Country Date 364,794 France June 9, 1906

